// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/surface/transport_dib.h"

#include <stddef.h>
#include <stdint.h>
#include <sys/stat.h>
#include <unistd.h>

#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/shared_memory.h"
#include "build/build_config.h"
#include "skia/ext/platform_canvas.h"

TransportDIB::TransportDIB()
    : size_(0)
{
}

TransportDIB::TransportDIB(TransportDIB::Handle dib)
    : shared_memory_(dib, false /* read write */)
    , size_(0)
{
}

TransportDIB::~TransportDIB()
{
}

// static
TransportDIB* TransportDIB::Create(size_t size, uint32_t sequence_num)
{
    TransportDIB* dib = new TransportDIB;
    if (!dib->shared_memory_.CreateAndMapAnonymous(size)) {
        delete dib;
        return NULL;
    }

    dib->size_ = size;
    return dib;
}

// static
TransportDIB* TransportDIB::Map(Handle handle)
{
    scoped_ptr<TransportDIB> dib(CreateWithHandle(handle));
    if (!dib->Map())
        return NULL;
    return dib.release();
}

// static
TransportDIB* TransportDIB::CreateWithHandle(Handle handle)
{
    return new TransportDIB(handle);
}

// static
bool TransportDIB::is_valid_handle(Handle dib)
{
    return base::SharedMemory::IsHandleValid(dib);
}

SkCanvas* TransportDIB::GetPlatformCanvas(int w, int h, bool opaque)
{
    if ((!memory() && !Map()) || !VerifyCanvasSize(w, h))
        return NULL;
    return skia::CreatePlatformCanvas(w, h, opaque,
        reinterpret_cast<uint8_t*>(memory()),
        skia::RETURN_NULL_ON_FAILURE);
}

bool TransportDIB::Map()
{
    if (!is_valid_handle(shared_memory_.handle()))
        return false;
#if defined(OS_ANDROID)
    if (!shared_memory_.Map(0))
        return false;
    size_ = shared_memory_.mapped_size();
#else
    if (memory())
        return true;

    size_t size;
    bool success = base::SharedMemory::GetSizeFromSharedMemoryHandle(
        shared_memory_.handle(), &size);
    if (!success || !shared_memory_.Map(size))
        return false;

    size_ = size;
#endif
    return true;
}

void* TransportDIB::memory() const
{
    return shared_memory_.memory();
}
